# downgrading from 3.4 to 3.3 **URL:** \ **Category:** CyanLabs Update Support\ **Tags:** SYNC3, APIM, retrofit, pre-my20, na, nav\ **Created:** [14 September 2025 05:35 UTC](https://community.cyanlabs.net/t/downgrading-from-3-4-to-3-3/23323 "2025-09-14T05:35:42Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![nbd3613](https://community.cyanlabs.net/user_avatar/community.cyanlabs.net/nbd3613/32/18092_2.png) [@nbd3613](https://community.cyanlabs.net/u/nbd3613)\ **Post date:** [14 September 2025 05:35 UTC](https://community.cyanlabs.net/t/downgrading-from-3-4-to-3-3/23323/1 "2025-09-14T05:35:42Z")
hello! i have a 2016 apim that i was using on 3.4. i wanted to downgrade to 3.3 to play with for a while as i never rlly experianced it before. i got it downgraded but i am having a few issues. if i start the car it will say navigation fault. the only way around this is to turn the radio on before i start the car it works. my other issue is when i disconnect carplay the system will say audio off and will not let me turn audio on unless i force restart the apim. are there any fixes for these issues? or do i just need to go back to 3.4 and call it a day. i would really like to get this working if its possible. * * * **SYNC Region:** NA **Navigation Variant:** Nav **Manufacturer Year:** Pre MY20 **Install Type:** Retrofit **Old SYNC Version:** 3.4 **New SYNC Version:** 3.3 **Do you have a error message, if so what is it?** navigation fault, audio off **Update Method:** CyanLabs Syn3 Updater **Syn3 Updater Version:** latest **Syn3 Updater Documentation Read:** yes **Syn3 Updater Log File** ```no-highlight none ``` ---
**Author:** ![warlock12118](https://community.cyanlabs.net/letter_avatar_proxy/v4/letter/w/e95f7d/32.png) [@warlock12118](https://community.cyanlabs.net/u/warlock12118)\ **Post date:** [14 September 2025 16:58 UTC](https://community.cyanlabs.net/t/downgrading-from-3-4-to-3-3/23323/2 "2025-09-14T16:58:51Z")
That would be because your maps are for 3.4.x you need to go back to 3.4.x 2016 Fusion was a transition year, its a one off in some cases with wiring harnesses and module firmware. On the 2016 Fusion a few people had cluster compass direction issues going to Sync3, the fix for that was to get a USED (not a new one) 2017 Fusion GWM (OBD2 port module). ---
**Author:** ![F150Chief](https://community.cyanlabs.net/user_avatar/community.cyanlabs.net/f150chief/32/14712_2.png) [@F150Chief](https://community.cyanlabs.net/u/F150Chief)\ **Post date:** [14 September 2025 17:17 UTC](https://community.cyanlabs.net/t/downgrading-from-3-4-to-3-3/23323/3 "2025-09-14T17:17:12Z")
Upudate the firmware on the APIM to MY18.5+ and it will likely fix your issues You will need a Sync 3.3 or later Strategy file. Keep in mind that using older OS files with newer NAV files will have some inconsistencies. > [@APIM Firmware Production Releases](https://community.cyanlabs.net/t/apim-firmware-production-releases/4686): > > Sync 3 APIM Firmware Production Releases (NA) NOTE: This listing is representative of the production release files for North America. Use the Calibration File Region listing below to determine the proper -14G375- calibration file for your region. POST-MY18.5: 3.4 APIM NAV & NON-NAV Unit Firmware (Production Release, 2021+ L Series) Secondary Boot Loader: GB5T-14G376-AA Strategy (F188): 1U5T-14G374-EM (7/13/2022) Calibration (F124): 1U5T-14G375-DA (NAV) / 1U5T-14G375-CA (NON-NAV) ECU Configu… ---
**Author:** ![system](https://community.cyanlabs.net/letter_avatar_proxy/v4/letter/s/bcef8e/32.png) [@system](https://community.cyanlabs.net/u/system)\ **Post date:** [8 October 2025 01:36 UTC](https://community.cyanlabs.net/t/downgrading-from-3-4-to-3-3/23323/4 "2025-10-08T01:36:34Z")
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